[Caoimhan]

The trouble with reversible chemical reactions is, if you split a molecule (Z) into smaller molecules A and B, producing a certain amount of energy for use elsewhere, to recombine A and B to get back Z usually takes at least the same amount of energy that splitting them did.

Correct the "usually" and say "always". Reversible chemical reactions use the same amount of energy in one direction as they produce in the other.

Even when a catalyst is used on one side of the reaction?

[EnergySpin]

The trouble with reversible chemical reactions is, if you split a molecule (Z) into smaller molecules A and B, producing a certain amount of energy for use elsewhere, to recombine A and B to get back Z usually takes at least the same amount of energy that splitting them did.

Correct the "usually" and say "always". Reversible chemical reactions use the same amount of energy in one direction as they produce in the other.

Even when a catalyst is used on one side of the reaction?

Catalysts never decrease the Delta G of the reaction ... they just make the path to the reaction easier to follow. Google : transition state catalyst enzymes etc

[gg3]

Kylon, if you've got something, post the technical details here with enough specificity that anyone with appropriate background can replicate your results.

Otherwise we can assume you were just positing a "what-if" and don't really have anything.